Histopathology of spontaneous abortion material: A comparative study of 403 cases

Four hundred and three patients with early spontaneous abortion were studied. Histopathological examination of aborted tissue was limited to a search for chorionic villi only in 312 patients, of whom 39-42 per cent were negative for chorionic villi. None of these patients suffered any sequelae on follow-up, demonstrating that histological detection of chorionic villi is not essential for diagnosis of intrauterine pregnancy, and their non-detection does not indicate an ectopic implantation. A further 91 patients were evaluated for the presence of chorionic villi and other recognised features of intrauterine implantation. Of this second group, only 29 per cent lacked definitive features of intra-uterine implantation. Again, no patient suffered any sequelae. These figures demonstrate improved accuracy of recognition of intra-uterine pregnancy and substantially reduced potential for incorrect diagnosis of ectopic pregnancy by using broader histological criteria. This stresses the value and importance of assessing the histological features of pregnancy in products of conception.